Apparatus for coating metal sheets



March 26, 1940. J. E. ELSWICK APPARATUS FOR COATING METAL SHEETS Filed Feb. 24, 1938 2 Sheets-Sheet 1 INVENTOR 1 John E. E lswicK Y ,M+M

J. E. ELSWICK I APPARATUS FOR COATING METAL SHEETS March 26, .1940.

2 Sheets-She et 2 Filed Feb. 24, 1938 NN. M x \I f k. N! m %N .MN m m w 3 R Ir L1 L1 INVENTOR John ElswicK Patented Mar. 26, 1940 a UNITED STATES PATENT OFFICE APPARATUS FOR COATING METAL SHEETS V s John E. Elswick, Steubenville, Ohio Application February 24, 1938, Serial No. 192,267

' 6 Claims. (01. ill-42.5)

This invention relates to apparatus for coating entering chamber 9 and a discharge chamber I0. metal sheets and more particularly to apparatus A passageway II in the partition 8 connects the for coating ferrous sheets with tin to form what chambers 9. and Ill. The height of the molten tin is known as tinplate. is indicated by the dot-and-dash line l2 and the 5 In the production of tinplate; the base sheets height of the flux is indicated by the dot-and-V 6 are first pickled and then dipped into pure molten dash line I 3. v tin.- The tin forms an alloy with the surface of The mechanism for feeding the base sheets the ferrous sheet to which a layer of tin adheres. through the flux and molten tin comprises three To insure a good bond between the base sheet pairs of feed rolls l4, l5 and I6 mounted be- 1 10 and the tin, it is necessary that the sheetsbe tween two housings l1 and I8. Astrut l9 secured 1 fluxed; This is accomplished by the use of a flux to the housings IT and I8 by angles braces the consisting usually of a mixture of zinc and amhousings at their lower ends and carries a block monium chlorides, which is floated on aportion 2| which provides additional support to the lower of the surface of the molten tin and is kept in a feed rolls l6. fused state by the heat of the molten tin. Guides 22 and 23 insure that the sheets in pass- 15 In the coating operation the sheets are passed ing from the feed rollers |5- will enter the nip into the tin pot by hand or machine and are car-, of the feed rollers IS. The guide 23 extends beried by suitable mechanical means r through the tween the housings I1 and I8 and serves as addiflux and the molten tin and out through a layer tional bracing. The guide 22 is pivoted about the of palm oil which covers another portion of the bolt 24 and may be adjusted by means of the 2 surface of the molten tin. bolt 25 which moves in the slot 26.

The flux has a tendency to oxidize and form a The bottom roll of the feed rolls i6 is driven hard surface which causes foreign particles to from a suitable source of power through miteradhere to the sheets as they are passed through gears 21 and is geared to the upper roll of the the flux. The adherence of these foreign parfeed rolls l6 by the pinions 28. The upper feed if ticles to the sheets causes a defective tin coating rolls M are connected to a suitable source of and the sheets must be scrapped or sold as secpower bigthe chain 29 and sprocket wheel 30. onds. Formation of this hard surface may be A chain hook 3| is provided by means of which prevented by continuous agitation of the surface the entire apparatus may be lifted out of the tin 30 of the flux. It is the purpose of my invention to pot I when desired. A chain hook 82 detachably provide apparatus for timing metal sheets in connected to the partition 8 by a yoke 33 and a which the surface of the flux is continuously agiset screw 34 is provided for moving the pot by tated and defects in the coating of the sheets means of a crane. are'preventem/ A dot-and-dash line 36 indicates the path of In the accompanying drawings I have illus-' the base sheets through the flux and molten tin. 86 trated a'present preferred embodiment of my in- The" flux is agitated by a rake which extends vention in which down into the slag to the surface of the molten Figure 1 is a transverse vertical section of the tin. This rake is moved back and forth across assembled apparatus along the lines I I of Figthe surface of the slag adjacent to the plane of 40 11 6 the base sheets by mechanismvwhich will now be Figure 2 is a longitudinal section of the assemdescribed. Brackets 31 bolted to the sides of the bled apparatus along the lines 11-11 of Figtin pot support sleeve bearings 38. Brackets 39 ure 1, extend from the brackets 3'! at right angles there- Figure,3 is a longitudinal section of a holder to and support a bar 40 which braces the ends used in my apparatus, I of the brackets 31. A right-and-left hand V Figure 4 is a transverse section along the lines threaded shaft 4| is mounted on the bearings 38 IVIV of Figure 3, and is turned by achain 42 which passes over a Figure 5 is an elevation view of the follower sprocket wheel 43 secured to the shaft 4| and a contained within the guide shown in Figures} sprocket wheel 44 mounted on the same shaft as and 4, and the sprocket wheel 30, which drives the entering 50 Figure 6.is a plan view of the follower shown feed rolls l4. The rake 351s carried by a holder in Figure 5. designated generally by the reference numeral Figures land 2 show the arrangement of my 45 which moves back and forth along the entire apparatus. A tin pot which'holds the threaded portion'of the shaft 4|. molten tin is divided by a partition 8 into an Figures 3 and 4 illustrate the mechanism by I which the holder 45 is caused to move back and forth along the shaft 4|. Two bushings 46 fit about the shaft 4| and carry a casing 41. A retainer 48 is bolted to the casing 41 and forms' As. the shaft 4| revolves, the follower 5| will slide in the threads 52 of the shaft and thereby be forced along the shaft 4|. As the follower moves along the shaft 4| it will carry with it the follower block 50 and consequently the entire holder 45. When the holder 45 reaches either end of the threaded portion of the shaft 4|, continued revolution of the shaft will cause the follower block 50 and follower 5| to rotate about a vertical axis and engage the set of threads which is cut in the opposite direction from the set with which the follower had previously been engaged. The oppositely cut threads will then cause the follower 5| and thereby the holder 45' 1to move across the tin pot 1 in an opposite direc ion.

The rake 35 slides into a sleeve and is retained in position therein by a set screw 56. The depth to which the rake extends into the flux may thereby be easily adjusted. A tongue 51 is welded to the top of the sleeve 55 and fits into a groove 58 cut in the retainer 48. It is held in the groove by the pin 59.

The rake is thus caused to reciprocate across the surface of the flux adjacent to the plane in which the base sheets enter the flux. The

continuous agitation of the flux prevents the 1. Apparatus for coating metal sheets with tin comprising a pot adapted to hold a bath of molten tin with a layer of flux thereon, means for feeding the metal sheets to be tinned through said bath, stirring means extending into said flux, a right-and-left hand threaded shaft for driving said stirring means across the pot, and a holder supporting said stirring means and having a follower cooperating with the threads of said shaft.

2. Apparatus for coating metal sheets with tin comprising a pot adapted to hold a bath of molten tin with a layer of flux thereon, means for feeding the metal sheets to be tinned through said bath, stirring means extending into said flux and means for impartingto said stirring means a reciprocating motion across the pot.

3. An agitator for stirring flux in a tinning pot comprising stirring means extending into the flux, a threaded shaft for imparting to the stirring means a reciprocating motion along the surface of the flux, a holder cooperating with said shaft and-supporting said stirring means, and driving means for revolving the shaft.

4. An agitator for stirring flux in a tinning pot comprising stirring means extending into the flux, a right-and-left hand threaded shaft for imparting to the stirring means a reciprocating motion along the surface of the flux, a holder supporting said stirring means and having a follower cooperating with the threads of said shaft, and driving means for uni-directionally revolving the shaft.

5.. An agitator for stirring flux in a tinning pot comprising stirring means extending into the flux, a shaft having threads cut therein for imparting to the stirring means a reciprocating motion along the surface of the flux, a guide cooperating with said shaft and supporting said stirring means, a follower turning in said guide and sliding in the threads of the'threaded shaft, and driving means for revolving the shaft.

6. Apparatus for stirring flux in a tinning pot comprising a shaft extending across the tin pot, stirring means mounted for movement longitudinally of the shaft, and means effective upon uni-directional rotation of the shaft for reciprocating the stirring means.

' JOHN E. ELSWICK. 

